22
EN/US/CA/A.mist A.mistT/UM-2239-1
Subject to alteration without prior notice.
FAULT TRACING
14
Mal-
function
Possible cause /
Action
Low capacity
(air flow)
The fan rotates in the wrong direction.
Action:
Check that the fan rotates according to the arrow on the motor
(only skilled personnel).
With VFD (frequency converter): The fan speed is set too low.
Action:
Check/adjust the fan speed (rpm/Hz) (only skilled personnel).
High pressure drop in the duct system.
Action:
Measure the negative pressure in the filter unit’s inlet plenum (before filter stage 1) and
compare with the “available external pressure drop” under “Technical data”. Check the damper
adjustment. Is the duct system sized for the actual airflow and filter unit?
The filter cassettes are clogged.
Action:
Check the pressure drop. If the yellow or red LED is lit for one of the filter stages, the
cassette should be replaced.
Abnormally short service interval
for filter stage 1:
Too much oil in the inlet plenum because of no or improper oil drainage from the filter unit.
Action: Make sure that drainage is provided for. Use one of the liquid traps described under
“Accessories”.
Sticky and or solid particles form a face loading.
Action: Look at the position of the suction point in the machine. Is it possible to move or pro-
tect the inlet with a shield to decrease the amount of sticky and solid particles sucked into the
filter unit? A pre-filter or spray system could also be a solution.
Chips and swarf is sucked in to the filter unit.
Action: Look at the position of the suction point in the machine. Is it possible to move or pro-
tect the inlet with a shield to decrease the amount of solid particles sucked into the filter unit?
A pre-filter could also be a solution.
Poor drainage from the cassette because of high viscosity (sluggish liquid particles).
Action:
If the fluid in the process has a high viscosity, it is necessary to add fluid with a spray
system (see “Accessories”).
The pollution is too dry.
Action: Look at the position of the suction point in the machine. Is it possible to move it so that
it sucks more liquid?
A spray system could also be a solution.
If emulsion is used, the filter cassette may dry out as the water in it evaporates if the unit is
running when production has stopped.
Action:
Switch off the filter unit when it is not in use.
Abnormally short service
interval for filter stage 2
or the HEP
A filter:
Too much oil in the inlet plenum because of no or improper oil drainage from the filter unit.
Action:
Make sure that drainage is provided for. Use one of the liquid traps described under
“Accessories”.
Air leakage past the preceding filter stage(s) because of incorrectly positioned filter cassettes
or damaged sealing strips. This results in unfiltered air reaching filter stage 2 / the HEPA filter.
Action:
Check that filter stages 1 and 2 are locked in position.
Check that the sealing strips of
filter stages 1 and 2 are undamaged and facing upward.
Particle overload because of a too high particle load (mg/m³) or too high fraction of small par
-
ticles.
Action:
Measure the particle load before the filter unit, after filter stage 1 and after filter stage
2. Check with the guidelines if this filter unit is suitable for the application and if there are any
options. Contact Absolent or your local distributor if you need advice.
